<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<style>
		*{margin: 0;padding: 0;}
		#box{width: 840px;height: 200px;background: red;}
		#box div{background:yellow;float:left;width: 200px;margin-right: 10px;height: 200px;}
	</style>
	<body>
		<div id="box">
			<div class="box-top"></div>
			<div class="box-bottom"></div>
			<div class="box-top"></div>
			<div class="box-bottom"></div>
		</div>
	</body>
</html>
